ERIC EJ973202: An Evolving Controversy: The Struggle to Teach Science in Science Classes

2012·0.33 MB·English

by  ERIC

An Evolving Controversy
The Struggle to Teach Science in Science Classes
By Michael Berkman and Eric Plutzer Like many researchers who are interested in K–12 education,
we are overall very pleased with the proposed Framework and are
E
veryone from President Obama to the average parent eager to see it developed into a new set of standards to guide
seems to agree that the STEM fields—science, technol- instruction.* And yet, as political scientists who have studied
ogy, engineering, and mathematics—are critical to the America’s long-running debate over teaching evolution versus
nation’s future. But, according to the National Research creationism, we bring a unique perspective to the question of
Council, “too few U.S. workers have strong backgrounds in these implementing any new standards based on the Framework. We
fields, and many people lack even fundamental knowledge of have not only examined the history of the evolution debate as well
them.” The only solution is “a new approach to K–12 science edu- as ongoing polls of public opinion, but also conducted a nation-
cation in the United States.”1 Last year, the Council took the lead ally representative survey of how high school biology teachers
in developing that new approach when it released A Framework deal with evolution in the classroom. We see a rough road ahead
for K–12 Science Education: Practices, Crosscutting Concepts, and for teachers.
h Core Ideas. Our findings are relevant to all K–12 science instruction
c
RGE BLO Michael Berkman and Eric Plutzer are both professors in the Department bFreacmauewseo trhk ew willi mdeaskper eevaodl uatdioonpatriyo nbi oolfo sgtya nmduacrhd ms boares esadl ioenn tt fhoer
Y SE of Political Science at Pennsylvania State University. Together, they wrote many teachers who have never before had to teach it. The new
ONS B Evolution, Creationism, and the Battle to Control America’s Classrooms Framework posits evolution as one of four core ideas in the life
iLLUSTRATi (rinaNcgetiweosn Y:, o PDrokCl:i :tC iGcasem oarbngrdeid tPoguweb Unl inUci nOveipvrisenirtsiyoi tPnyr Piensrs eA,s 2ms0, 21e00ri)0c 5aa)n’s.d S Tcehno oThl Douisstarincdts D (eWmaoshc-- scceinetnrcael sto. H thigeh b sicohloogoyl tceuarcrhiceurslu wmil.l Sboe eimxppeocrtteadn tto i sm eavkoel uetvioolnu ttihoant
*That work is under way. To learn more, see
www.nextgenscience.org. For a review of the
12 AMERicAN EdUcATOR | SUMMER 2012 framework, see http://bit.ly/zdLFc1.
the Framework’s building blocks for understanding evolutionary tions subject to peer review. Initial findings from laboratory
biology begin as soon as children enter school. By the end of sec- experiments or from field data are written up as scientific papers.
ond grade, for example, children are supposed to know that Those papers, too, are subject to peer review; if published in sci-
“Some kinds of plants and animals that once lived on Earth (e.g., entific journals, they reflect both the insights of the authors and
dinosaurs) are no longer found anywhere, although others now the confidence that qualified experts have in the methods and
living (e.g., lizards) resemble them in some ways.”2 Because such logic employed by the investigators. Anonymity allows peer
early preparation is rare among state standards today, elementary reviewers to raise frank criticisms about findings whenever labo-
and middle school educators have generally escaped the evolu- ratory procedures, fieldwork, or statistical analyses are question-
tion wars that have ensnared many high school biology teachers; able. Yet, in spite of the high hurdles to winning research funding
but once standards based on the Framework are implemented, and publication, scientists do regard published findings as tenta-
these teachers will be expected to provide students with founda- tive; replication by other laboratories and scientific teams is
tional concepts in preparation for studying evolution in some encouraged and is, in fact, commonplace. It is only after findings
depth during high school. have been replicated many, many times that scientists begin to
Moreover, with increasing politicization in our society of consider them “facts.” Modern evolutionary science rests on a
astronomy (big bang), health (vaccines), and especially earth sci- foundation of such facts.
ence (climate change), controversy could become the new normal
for K–12 science study. That would be tragic. Understanding the
challenges of teaching evolution has increasing relevance, there-
fore, across the science curriculum and speaks to more general
debates concerning the importance of teachers having deep
With increasing politicization in
content knowledge.
our society of astronomy (big bang),
Evolution: from darwin to Today’s Consensus
health (vaccines), and earth science
Some teachers, we know, are taken aback by the confidence and
apparent brashness of evolution’s defenders. The National Acad- (climate change), controversy could
emy of Sciences flatly states that “there is no controversy in the
become the new normal for K–12
scientific community about whether evolution has occurred. On
the contrary, the evidence … is both overwhelming and compel- science.
ling.”3 More directly, biologist Jerry Coyne’s popular book is simply
titled Why Evolution Is True. Such a confident stance seems to
conflict with many nonscientists’, including many teachers’,
understanding of science. Many people think of science as a con-
stant search for new information—and thus always subject to
revision. Scientists themselves often contribute to this point of Indeed, there is no better example of how tentative individual
view. The American Association for the Advancement of Science’s findings can accumulate to highly confident conclusions than the
statement on the nature of science,4 for example, notes: work of Charles Darwin himself. His initial 1859 publication of On
the Origin of Species went through many printings, editions, and
Science is a process for producing knowledge. The process
translations; by 1900, most educated people in Europe and North
depends both on making careful observations of phenomena
America were familiar with its ideas. Meticulous in its presenta-
and on inventing theories for making sense out of those
tion of evidence, written in a style that remains accessible to
observations. Change in knowledge is inevitable because new
nonexperts, and rich in its description of the natural world, Dar-
observations may challenge prevailing theories. No matter
win’s compelling argument about common ancestry offered a
how well one theory explains a set of observations, it is pos-
theoretical understanding of what naturalists had long observed:
sible that another theory may fit just as well or better, or may
dogs resemble wolves, housecats resemble tigers, and apes
fit a still wider range of observations. In science, the testing
resemble human beings.
and improving and occasional discarding of theories,
To read On the Origin of Species is to be invited inside the mind
whether new or old, go on all the time. Scientists assume that
of a scientist who questions everything, responds fully to actual
even if there is no way to secure complete and absolute truth,
and anticipated challenges to his conclusions, and understands
increasingly accurate approximations can be made to
that his argument will not stand or fall based on any individual
account for the world and how it works.
finding. Darwin had conceived the basic ideas of common ances-
In this light, some teachers have told us that the emphatic try and natural selection much earlier, but engaged in a 22-year
endorsement of evolution and the denial that there are “two sides” process of accumulating evidence before publishing the work. He
can seem immodest or arrogant. Yet such a view fails to appreciate sought out and carefully analyzed evidence from mollusks, bar-
that when a theory survives decades of rigorous testing—as evolu- nacles, and jellyfish; from ants, wasps, and snakes; from pigeons,
tion has and its opposing assertions have not—scientists are justi- mockingbirds, and flightless birds as well as the finches he had
fied in their high confidence in the theory. observed on the Galápagos Islands. He conducted his own experi-
Today, most scientific research is conducted by teams and is ments and corresponded with experts worldwide.
supported by research funds obtained through tough competi- Natural selection was the most innovative idea of Darwin’s
AMERicAN EdUcATOR | SUMMER 2012 13
book and is based on three well-established processes that (morphology). Most schoolchildren, using only their powers of
together lead to changes in populations of organisms. The first is observation, come to see that bats are more similar to mice than
that individuals within a population vary, and the variations can they are to birds, and that extinct mastodons were more similar
be inherited, so that the individuals of populations are genetically to modern elephants than to modern rhinos. Experts in compara-
diverse. The second is that, since population growth is restricted tive anatomy, of course, can make much finer distinctions using
by the resource availability in the environment, some individuals such characteristics as the shape of teeth or the arrangement of
within a population are more likely to survive than others. The bones in joints such as the knee, pelvis, or wrist. These relation-
third idea ties these two together: those individual organisms best ships among species, depicted in a tree diagram, imply a series of
able to secure resources or cope with environmental conditions testable hypotheses.
generally are the most likely to survive and to reproduce. The traits For example, phylogenetic trees in basic textbooks will show
that favored these individuals will then be passed to their that starfish are older (assumed to have arisen earlier) than bony
offspring. fish, which are in turn older than birds. This is clearly testable: if
Precisely how traits were passed on was not understood by bony fish were found in older geological strata than starfish, then
Darwin or his contemporaries. That understanding took decades, this portion of the tree diagram would be refuted. But the fact that
beginning with the rediscovery of Gregor Mendel’s 19th-century there are thousands of starfish fossils independently dated to be
research on heredity: natural selection older than the earliest known fossils of vertebrate fish provides
must act on hereditary determiners strong evidence for this aspect of the hypothesized evolu-
(genes) that, individually or in groups, tionary tree.
produce traits that are advantageous in a Such diagrams also imply
particular ecological setting. The develop- that there must have been
ment of population genetics in the first species that shared features
third of the 20th century showed that the with two or more other
natural selection of individual genes kinds of animals. These
could have profound conse- transitional features must
quences on the distribution of have emerged somewhere in
characteristics in popula- time between the species
tions of a particular species. shown. Hypotheses about transi-
That is, if the same traits tional features can be challenging
prove favorable for many generations, the because not every species lived
distribution of traits in the population as a continuously in conditions favor-
whole changes. able for preserving their remains
During the middle third of the 20th and because transitional forms
century, scientists obtained good evi- may have been short-lived. The
dence that, under certain conditions, absence of fossil evidence support-
natural selection can lead to the emergence ing a transitional feature is not
of altogether new species. For instance, if sufficient cause to reject the
members of the same species become physically separated and hypothesis that these species existed; it may just mean that fossils
are subjected to dissimilar environments—on different islands of of transitional species have yet to be discovered or that such fossils
an archipelago or on opposite sides of a mountain range—they never formed. Nevertheless, hypotheses concerning transitional
may, over time, display different adaptations and diverge. Given forms represent an important consequence of evolutionary mod-
enough time, these adaptive variations can produce organisms els, and biologists (as well as scientists in many other fields) find
no longer able to breed with their distant cousins, and the earlier it quite exciting when transitional species are discovered.
ancestral species may no longer exist in a recognizable form. Consider Tiktaalik, a fish, but with the first clear suggestion of
“When forces divide a single species into two populations,” writes wrists, elbows, and a neck. It was discovered in 2004 by biologist
biologist Kenneth Miller, “natural selection will act on each sepa- Neil Shubin and his colleagues, who had hypothesized that a spe-
rately, until they have accumulated enough differences that each cies showing transitional traits between water and land animals
becomes a separate (and new) species.”5 must have lived between 365 and 380 million years ago near both
Today, evolutionary theory is a framework that integrates Men- land and water. As told in Shubin’s engaging book Your Inner
del’s laws of inheritance, the three principles of natural selection, Fish,6 fossils of Tiktaalik were found exactly where expected, by a
our understanding of the process of genetic mutation, and popu- team painstakingly searching 375-million-year-old rock in the
lation genetics, along with embryology and paleontology. It yields Arctic in an area that at one time contained freshwater streams.
not only powerful explanations for the observed diversity of life, Hypotheses about common ancestry can also be tested
but also a cornucopia of testable hypotheses. through the genetic codes of living animals. By combining mod-
Striking examples of testable hypotheses come from the spe- ern genomics data with observed rates of genetic mutation, pow-
cialty of systematics—the specialty that produces branching erful computer programs are able to infer patterns of relationships
diagrams that show how species are related to one another (phy- among species. These programs do not include any information
logenetic trees). For more than a century, these diagrams repre- based on analysis of fossils or radioisotope dating; they group
sented hypotheses based primarily on comparative anatomy species based, for example, on similarities in mitochondrial DNA.
14 AMERicAN EdUcATOR | SUMMER 2012
By and large, however, the phylogenetic trees produced in this Much of the public also opposes teaching evolution in the
way are in remarkably close agreement with the traditional evo- classroom. Federal courts have consistently held that states and
lutionary trees based on observed anatomical traits. school boards cannot ban the teaching of evolution or introduce
Additional evidence comes from the field of developmental creationism, creation-science, or intelligent design into the public
evolutionary biology, which examines embryos that often display school curriculum. But significant segments of the public do not
vestigial features that do not appear in adults. Contemporary spe- care. Many do not accept the science, do not want it taught, or
cies grouped together in phylogenetic trees are hypothesized to prefer approaches that courts have repeatedly rejected as
share more developmental similarities than species classified as unconstitutional.
more distant. Again, many studies of animal embryos have pro- For example, a 2005 poll conducted by the Pew Research Cen-
vided independent and convergent evidence supporting these ter found that 57 percent of the public feels that creationism
hypotheses. should be taught “along with” evolution in the public schools, and
Although the details are subject to revision based on new and only 33 percent of the public opposes such a proposal. Indeed,
better evidence, the fundamental hypothesis of common ancestry among those opposing the proposal were many who feel it does
has been verified so many times, by so many independent kinds not go far enough. Once we account for those who would like to
of experiments spanning different scientific specialties, that there see creationism taught “instead of” evolution, this poll suggests
is no longer serious debate that evolution has occurred. This justi- that only 22 percent of the public supports teaching evolution and
fies confidence in the claim that, as much as any sound scientific only evolution.11 Other polls using different question wording lead
statement, evolution is true. to the same conclusion.12
What is often unappreciated—even by many well-educated Given that public sentiment is at odds with the nation’s scien-
tific organizations and in direct conflict with the rulings of
the U.S. Supreme Court, it cannot be easy to be a high
school biology teacher. Nor will it be easy for elementary
Federal courts have consistently held
and middle school teachers to meet the Framework’s
that states and school boards cannot expectation that they provide evolution’s conceptual
building blocks to younger students. Anti-evolution opin-
introduce creationism or intelligent
ion does vary across states and school districts, but even
in Massachusetts, the most pro-evolution state in the
design into the public school
country, we estimate that less than 50 percent of the pub-
curriculum. lic thinks evolution should be taught alone.13 In short,
polls show that anti-evolution sentiment runs deep in the
United States. Further examination shows that anti-
evolutionism is closely linked to certain faith traditions—
citizens—is that the branching diagrams in high school or college placing evolution squarely in the middle of contemporary
textbooks typically reflect many cycles of hypothesis, experiment, culture wars.
modification of hypothesis, and further experiment. They repre-
sent scientists’ best current understanding based on multiple and The religious roots of Anti-Evolutionism
independent tests from the sciences of dating, comparative In the mid-1800s, American Evangelicals were riven by divisions
anatomy, embryology, and genetics. Over time, as knowledge based on geography and race. These divisions would soon also
increases and as hypotheses survive rigorous testing, revisions to extend to theology, leading many southern and midwestern Prot-
such diagrams become less frequent and confined to small modi- estant churches to break away from their northeastern brethren.
fications. As a result, our confidence in these models increases Their religious principles slowly crystallized and were published
and specific evolutionary paths become accepted as fact.7 in a series of early 20th-century pamphlets called The Fundamen-
tals (hence the label Fundamentalist). Among the key elements
Public Skepticism of Evolution
in Fundamentalist theology was the assertion that the Bible and
By almost any yardstick, evolution science is thriving, and con- its creation stories are not only a guide to spiritual life and salva-
vergent evidence from multiple fields confirms its core ideas. And tion but also an authoritative textbook of human and natural
yet, many Americans continue to reject it. For years, the Gallup history—a textbook apparently in conflict with scientific accounts
polling organization has asked people whether they believe that of evolution.14
human beings were created “pretty much in their present form By the early 1920s, Fundamentalism was an energetic and
at one time within the last 10,000 years or so.” In a December 2010 thriving religious movement spreading well beyond its southern
poll, 40 percent of Americans chose this creationist response.8 roots. At the same time, because of the rapid growth of school
Similarly, the 2010 National Science Foundation’s Science Lit- enrollments, Fundamentalists came to view evolution as an
eracy surveys found that 39 percent of Americans believe it is not increasingly dangerous idea.15 If evolution was in conflict with
true that “Human beings, as we know them today, developed scripture, then its place in the public school curriculum was seen
from earlier species of animals.”9 Using slightly different wording, as a threat; this idea soon spread to individuals of other faiths. In
a 2007 Pew Forum poll found that 45 percent reject the idea that a statement intended as the closing argument in the Scopes “mon-
“Evolution is the best explanation for the origins of human life key trial,” William Jennings Bryan argued in 1925 that in colleges,
on earth.”10 “Evolution is deadening the spiritual life of a multitude of stu-
AMERicAN EdUcATOR | SUMMER 2012 15
dents” and would—if taught in secondary school—“poison the
minds of youth” and “destroy … religious faith.”16 This idea
remains central to anti-evolution politics today.
More than 80 years after Scopes, the legacy of the early
Fundamentalists can be seen clearly in contemporary public
opinion.17 Most of the leaders of creationist organizations
have come from this faith tradition,18 and these doctrinally
conservative churches are today among the fastest grow-
ing in the United States, keeping creationism in the
vanguard of anti-evolution politics. It is a tribute to
the energy and effectiveness of Fundamentalist clergy
and laity that many of their ideas, including biblical
inerrancy, are now embraced by individuals in other
denominations.19 Indeed, even though the clergy and
leadership in Mainline Protestant and Catholic churches
accept evolution, the data show that 35–45 percent of the
adherents in these traditions consider evolution false.20 Among
the larger American religions, only adherents to Judaism are over-
whelmingly accepting of evolution.
While doctrinally conservative churches are highly unified in tenth-grade
their opposition to evolution, there is not much consensus in biology teachers.
terms of what exactly they stand for when it comes to origins. Up Our survey is representative
until 1968, they fought to keep evolution out of public schools. But of schools across the country, and includes teachers from 49 states
after the Supreme Court ruled such bans to be unconstitutional, and 599 school districts. We asked each teacher about his or her
creationism itself evolved.21 For example, a small group of scien- classroom practices, personal beliefs, and pre-service education.
tists have developed arguments for intelligent design. Intelligent And we gave all teachers the opportunity to share their experi-
design creationists argue that the odds are close to zero that natu- ences in their own words.24
ral selection and mutation alone could account for complex Our survey allows us to benchmark actual teaching practices
biological features. Like all estimates of probability, these infer- to recommendations from the major scientific and science educa-
ences depend on sets of assumptions, such as the assumption that tion associations. Of course, the new Framework did not exist in
genetic mutations that confer advantages occur independently, 2007, but even then, the National Research Council (NRC), the
which is simply at odds with mainstream evolutionary National Science Teachers Association, and the standards issued
biology.22 by a few states endorsed a rigorous treatment of evolutionary biol-
Today, we find anti-evolution activists promoting all varieties ogy. Based on teachers’ answers to our questions, we are able to
of creationism; it is opposition to evolution that brings them sort teachers into three broad groups: advocates of evolutionary
together. In no small part, this is because the federal courts have biology, advocates of creationism, and a group we call the “cau-
made it difficult to introduce any kind of creationism directly into tious middle.”
the classroom through state legislation or school board directives.
But it also represents a hope that successfully undermining evolu- Advocates of Evolutionary biology
tion leaves creationism standing as the single and obvious alterna- Slightly more than a quarter of the teachers (28 percent) are
tive. Eugenie Scott of the National Center for Science Education clear advocates of evolutionary biology. These teachers gave
writes that the idea that evolution is scientifically controversial is pro-evolution responses to three questions that tap important
the first of the three pillars of modern creationism.23 The second recommendations from the NRC (and the strongest possible pro-
pillar is the effort to persuade religious Americans that evolution evolution answer to at least two):
and religion are incompatible, and the third is the idea that “to be
1. “When I do teach evolution (including answering student
fair,” both sides must be taught.
questions), I emphasize the broad consensus that evolution is
These three pillars are evident in the tactics of creationist activ-
fact even as scientists disagree about the specific mechanisms
ists and politicians. Apparently, they have been successful: we
through which evolution occurred.” (Agree or strongly agree)
have found that the three pillars of creationism are frequently
2. “Evolution serves as the unifying theme for the content of the
adopted by high school biology teachers, including many who
course.” (Agree or strongly agree)
would not consider themselves members of the anti-evolution
3. “I believe it is possible to offer an excellent general biology
movement.
course for high school students that includes no mention of
Teaching High School biology Darwin or evolutionary theory.” (Disagree or strongly
disagree)
Clearly, many science teachers work in communities with large
numbers of people opposed to evolution. How do teachers navi- Strong advocates confront each of the three pillars of modern
gate such a difficult situation? creationism. For one, they do not present evolution as a theory in
To find out, in 2007 we surveyed more than 900 ninth- and crisis in any way; they recognize and teach that evolution is an
16 AMERicAN EdUcATOR | SUMMER 2012
established scientific finding supported by evidence so over- suggests to students that one can find ways to reconcile religion
whelming it has taken on the status of scientific fact. And consis- and science. And none teach that creationism is an alternative
tent with the NRC’s recommendations (and those of its new explanation requiring any kind of equal time.
Framework), they lace evolution throughout their courses. To do
this, advocates of evolution spend, on average, 18.3 hours of class- Advocates of Creationism
room time on evolution. Their commitment to a thorough treat- We classified 13 percent of the teachers as advocates of creation-
ment of evolution came through in their comments. One Indiana ism because they spend at least one hour of class time on intel-
teacher, for example, wrote that “I tell students that I teach evolu- ligent design or creationism and use that time to present it in an
tion as a topic in biology because all other biological functions affirming manner, as indicated by their agreement with at least
are based in evolution,” while a Pennsylvania teacher stressed one of these two questions:
how evolution is a unifying theme when she said that “the natural
1. “When I do teach about creationism or intelligent design
selection process is interjected into almost every topic I cover.”
(including answering student questions), I emphasize that this
Many of these advocates use evolution to show how science
is a valid, scientific alternative to Darwinian explanations for
and religion ask different questions and how the aims of each
the origin of species.”
differ, therefore directly countering the idea that evolution is athe-
2. “When I do teach creationism or intelligent design (including
istic and incompatible with religious beliefs (the second pillar of
answering student questions), I emphasize that many repu-
creationism). They do this in different ways. Some use evolution
table scientists view these as valid alternatives to Darwinian
as a window into science more generally, while drawing contrasts
theory.”
with religion: “We compare the process, knowledge, societal value
and types of questions that are answered by both organized reli-
gion and science,” wrote one Ohio teacher. “We recognize each
serves a different purpose and they do not conflict.”
Others, well aware of student sensitivities, confront potential
opposition directly and proactively early in the academic year. A Given that public sentiment is at odds
teacher from Indiana summed up this approach: “I have been
with scientific organizations and the
able to present an extensive unit on evolution in an ultra-con-
servative rural school with minimal negative feedback. I have
U.S. Supreme court, it cannot be easy
done this by 1. trying to teach what science is, 2. how science and
religion ask different questions and 3. by presenting evidence to be a high school biology teacher.
that science and religion are not in conflict. I do this before
exploring the history of evolutionary theory and evidence that
evolution has/and is occurring.” And still others draw on their
personal faith: “My mother is a minister and I’m very familiar
with the Bible and have strong religious beliefs myself,” an Ari-
zona teacher told us. “I believe this helps me talk with my stu- Advocates of creationism both teach some creationism (at least
dents about their faith (outside of regular class time) and gives one hour) and minimize instruction in evolution. This is, of
me some extra credibility when I explain that you can believe in course, consistent with the modern creationist objective of under-
your religion AND evolution.” mining evolution. So teachers who advocate creationism spend,
Overall, strong advocates for evolution teach evolution not only on average, only 11.6 classroom hours on evolution, and some
as the NRC recommends, but in a way that gives little support to spend considerably less. As one Minnesota advocate for creation-
modern creationists. They clearly articulate evolution as an ism explained, “I don’t teach the theory of evolution in my life
accepted scientific fact. Many contrast it with religion in a way that science classes, nor do I teach the Big Bang Theory in my earth
science classes. There is just too much science and inquiry that
we do not have time to do something that is at best poor
science.”
An Illinois teacher both undercut evolution and spoke to the
modern creationist arguments that evolution and religion are
incompatible and that evolution cannot be studied
scientifically:
I am always amazed at how evolution and creationism are
treated as if they are right or wrong. They are both belief sys-
tems that can never be truly or fully proved or discredited as
man was not present at the beginning to satisfy his or her
curiosity as to the nature of the situation.
Of course, as the discovery of Tiktaalik teaches us, science can
most certainly be used to confirm hypotheses about what hap-
(Continued on page 20)
AMERicAN EdUcATOR | SUMMER 2012 17
(Continued from page 17) For the anti-evolution movement, the micro-macro distinction
pened in the past. By saying that a scientific discipline is a serves to directly undermine the status of the major findings of
“belief system,” teachers retreat from the idea that scientific evolutionary biology. “I distinguish microevolution as fact,” wrote
methods are how we learn about the natural world and reject an Indiana advocate of creationism, and “macroevolution as
the idea that science and faith speak to distinct and nonover- theory.”
lapping domains. However, most teachers in the middle group do not teach this
And yet, teachers who are advocates of creationism also sup- way in order to narrow the scope of instruction; rather, they use
port teaching both sides. This is implicit in the fact that they spend the micro-macro distinction to make the material less controver-
at least one hour on creationism and some time on evolution, but sial. So, for example, a teacher in California who offered sound
it comes through in their comments as well. One creationist pedagogical reasons for beginning with microevolution made it
teacher from Indiana, for example, told us that “in teaching biol- clear that she finds it less controversial to focus on this aspect of
ogy, I do not impart my belief on this subject to my students, I evolutionary theory:
present each idea as a theory and let the students decide which
I teach evolution through a cellular and molecular approach.
one they want to believe in.” And a teacher from South Dakota
I find students are less offended by it. The minute you start
who devotes eight hours to creationism and ten hours to evolution
off with evolution showing primates or fossil evidence, stu-
explained: “I teach evolution/creation as an inquiry process. I use
dents immediately shut down. On the other hand, when I
classroom text as well as other sources backing evolution/cre-
ation. I have several useful videos backing both areas. My goal is
to make students analyze and think to arrive at their own edu-
cated decisions.”
The Cautious Middle
Sixty percent of the teachers who completed the survey
do not fall into either group of advocates. These teachers
are in the cautious middle—a large and diverse group
that utilizes a range of strategies to navigate the chal-
lenges posed by the sometimes competing expecta-
tions of state standards, administrators, school board
members, students, and parents. About one in ten is a
cautious or closet creationist: they do not qualify as
“advocates” of creationism because they do not incor-
porate it into their lesson plans or spend as much as an
hour on the topic. However, these closet creationists tell
us that they validate creationism as credible science when
teach students the mechanisms of cells and that all cells basi-
prompted by student questions or comments.
cally are similar, then I can suggest evolution without so
Most teachers in this middle group, 85 percent to be exact,
much opposition.
accept evolution. What they have in common is that they cannot
or will not teach what the major scientific organizations expect: Pursuing this strategy may well limit exposure to angry parents
that evolution is central to all biology, that evolution has occurred, and skeptical students. But this approach also lends credence to
and that hypotheses from evolutionary theory have been con- a creationist claim that there is no evidence for one species giving
firmed by many scientific studies. Instead, they employ a suite of rise to others, and in doing so sacrifices a rich understanding of
techniques that reduce the likelihood of sparking some kind of the diversity of life. One of modern creationism’s three pillars is
controversy. In most cases, however, these are very nearly the that evolution—at least macroevolution—is not well-established
same approaches taken by explicit creationist educators in sup- science.* Excluding macroevolution, or teaching it as less scien-
port of the three pillars of modern creationism—approaches that tifically established, plays directly into creationists’ hands.
undermine students’ confidence in science more generally and Teaching to the Test: Statewide biology examinations are used
undercut their broader science education. Three controversy- in a growing number of states. In general, these examinations will
avoidance techniques were mentioned often enough to merit promote more rigorous instruction in evolution so long as they
some discussion: distinguishing between micro- and macroevo- are aligned with fairly rigorous standards.26 And a teacher may
lution, teaching to the test, and encouraging students to make up enjoy some protection to teach the topic if the standards and tests
their own minds. require it.† But teachers in the cautious middle can also use these
Micro- vs. Macroevolution: One common strategy to avoid stir- tests as a means to disassociate themselves from the very material
ring the deep feelings associated with evolution is to teach evo- they are expected to teach. In different ways, they defend their
lutionary biology as though it only applies to within-species
change—often called microevolution. Teachers adopting this *The well-known creationist Henry Morris put this well when he said that “the fact
that macroevolution (as distinct from microevolution) has never been observed would
tactic deny their students exposure to a large body of evidence
seem to exclude it from the domain of true science.”25
showing how natural selection leads to speciation and to the
†For an interesting news feature about how a Georgia teacher used state standards to
central concept of common ancestry of contemporary species. navigate community pressure and teach evolution, see http://nyti.ms/GLmw6b.
20 AMERicAN EdUcATOR | SUMMER 2012
teaching of evolution as a necessary evil, something students just of creationism as well because the “fairness” of teaching both
need to get through. One Michigan teacher tells her students that sides is one of the three pillars of modern creationism. An Okla-
they need to understand evolution because the biology curricu- homa teacher who was clear about her creationist beliefs and
lum “is organized as if evolution is true.” A New York teacher said, teaching policy was emphatic about this: “To be a true scien[tist],
“I have always started the evolution unit by telling the kids that I you have to present both evolution and creationism!” Another
don’t care if they believe in evolution or not…. Just understand it teacher, from Iowa, described her approach this way: “I let the
enough to answer the Regents test questions.” Like many explicit students know up front that I have a creationist view point of how
creationist teachers, this teacher treats the acceptance of evolu- life was created. I use the word ‘model’ to explain evolution (‘evo-
tion as something students can choose to “believe in” and—inten- lution model’). I bring in the ‘intelligent design model’ to question
tionally or not—undercuts the principle that scientific methods the ‘evolution model.’ ”
are how we learn about the natural world. Whether the teacher is trying to introduce creationism, hoping
More generally, when teachers disassociate themselves from to avoid controversy, or simply manifesting great confidence in
the science by invoking the test, they undermine evolution in students’ ability to learn by exploration, the effect is the same. One
students’ minds. After all, a teacher would never tell students that teacher put it this way: “I encourage students to gather as much
he or she did not care if they actually believed that light simultane- information as possible and make their own conclusions.” But it
ously has the properties of waves and of discrete particles, or that is simply not realistic to expect that, with only 10–15 class hours
the movement of massive plates is the cause of earthquakes. devoted to evolution, students are really equipped to assess and
perhaps reject the thousands of peer-reviewed scientific
papers that form the empirical foundation of evolution-
ary theory. This approach tells students that science is
not a cumulative body of highly technical knowledge,
it is not realistic to expect that students but is instead something that has some element of per-
sonal preference, like whether Claude Monet created
are equipped to assess and perhaps
more beautiful paintings than Paul Cézanne.
reject the thousands of scientific We have argued in the past that the cautious 60
percent may play a far more important role in hinder-
papers that form the empirical
ing scientific literacy in the United States than the 13
percent who are explicit creationist advocates.28 The
foundation of evolutionary theory.
strategies of emphasizing microevolution, justifying
the curriculum on the basis of statewide tests, or
“teaching the controversy” are precisely the tactics
employed by advocates of creationism. Creationists
use these approaches because they undermine the
Among established scientific principles, only evolution is so fre- legitimacy of findings that are well established by the combina-
quently approached as something that students need to know for tion of peer review and replication. They make it difficult for
the test, not because it is solid science. Indeed, an explicit advo- students to reconcile their religious beliefs with the established
cate for creationism—a teacher from Texas—used nearly identical science. And they have the veneer of fairness. Afraid of doing
language when she told us that “I tell my students to learn the anything that might upset student sensibilities, many of these
information for purposes of only passing the state test to cautious teachers may not fully explain the nature of scientific
graduate.” inquiry; as a result, they undermine the authority of estab-
Students are no doubt smart enough to pick up the message lished scientific experts and promote creationists’ political
that underlies “just learn it for the test.” And we expect that in the goals, even if unintentionally.
future, some teachers will be tempted to use the same tactics of
Sources of Ambivalence and
disassociation in order to avoid controversy concerning topics
Conflict Avoidance
like climate change.
Students Should Make Up Their Own Minds: A third strategy If most teachers in the cautious middle accept evolution per-
used by teachers in the cautious middle is to argue that students sonally, why do so many employ pedagogical approaches
should be exposed to explanations other than evolution—scien- championed by the anti-evolution movement? Our research
tific or not. This, more than any other coping strategy, plays suggests that many teachers do not feel like they have the
directly into the creationists’ hands. Bills and policies requiring expertise they need to confidently teach evolutionary biology
or encouraging teachers to “teach the controversy” or to teach the in a rigorous and unapologetic manner.29 Those with inade-
“gaps” in evolution are an increasingly popular creationist tactic quate content knowledge find that teaching evolution makes
to undermine evolution. In many cases, these arguments are their jobs even more stressful; therefore, they gravitate toward
advanced as supporting “critical thinking” or “critical analysis.”27 strategies that reduce the likelihood of generating controversy.
Students should make up their own minds, explained a Pennsyl- We can see evidence of this when we compare the responses
vania teacher, “based on their own beliefs and research. Not on of our three groups with a variety of questions pertaining to
what a textbook or on what a teacher says.” teachers’ pre-service education and personal assessments of
This approach of letting students decide is used by advocates how well they understand evolution.
AMERicAN EdUcATOR | SUMMER 2012 21
Teachers’ Content Knowledge ing on the validity of evolutionary theory as”: “Exceptional, on par
with many college-level instructors”; “Very good compared to
States’ wide variety of certification requirements virtually ensures
most high school biology teachers”; “Typical of most high school
that not all science teachers are equally knowledgeable about
biology teachers”; or, they could admit, “I know less about this
evolutionary theory or science generally. A study of Indiana biol-
topic than many other high school biology teachers.”
ogy teachers, for example, found that many do not “possess a
The question produces something of a “Lake Wobegon” effect,
thorough knowledge of evolutionary theory and its place in the
discipline of biology.”30 as 61 percent rated their knowledge as “above average” or “excep-
tional” and only 2 percent rated themselves below average. None-
In our survey, we asked teachers about their pre-service col-
theless, the self-assessments of teachers form a striking pattern:
lege education. In the figure below, the set of bars on the left
teachers in the cautious middle are, once again, statistically
shows the percentage of teachers in each group who have com-
indistinguishable from creationism advocates.
pleted a standalone course in evolution. This one indicator of
We also found that more science training in general makes a
teacher knowledge has a dramatic effect. More than 50 percent
difference. For example, we found that the higher
of the teachers who advocate evolution
the number of college credit hours in biology, the
(green bar) have taken a college-level
more that teachers keep up with scientific
course in evolution. Only a third of the
advances by visiting science education websites,
teachers who advocate creationism, on
noting changes in new additions of their text-
the other hand, took such a course.
books, and browsing scientific journals.
Teachers in the cautious middle
Not surprisingly, these related experi-
look much like creationists, with
ences are more common among teach-
slightly more than a third having
ers who rated their knowledge of
completed a course in evolution
evolution as exceptional. Teachers
(the small difference is not sta-
with more extensive content-based
tistically significant).
preparation are also much less likely to agree
Additional evidence is found in the
with the statement that “I have paced my class so
set of bars on the right in the figure. For
that the evolution chapters in my textbook would be cov-
this, we asked each high school teacher to rate his
ered only minimally at the end of the academic term,”
or her “knowledge of the scientific evidence bear-
another common avoidance strategy.
Why did we find that completing a college-level evolution
Percentage of teachers in each group course is so strongly related to teaching practices? Part of the
who completed a college-level course on answer is that many pre-service teachers who do not accept evo-
evolution and who rated their knowledge lution will not select such a course as an elective. Overall, we have
of evolution as above average or found that teachers who expressed creationist beliefs completed
exceptional. fewer courses in biology, were slightly less likely to major in a
scientific field, and were considerably less likely to hold a graduate
Advocates of evolutionary biology degree in a scientific discipline.31 However, for the 85 percent of
Cautious middle 82% teachers in the cautious middle who accept evolution, the com-
Advocates of creationism pletion of an evolution class provides content knowledge that
translates directly into self-confidence. In many districts, teachers
understand that each additional class hour devoted to evolution
increases the likelihood of offending a student or getting an angry
visit from a parent or local minister. Self-confidence is an impor-
56%
54% tant factor in how teachers approach these classes.32 While evolu-
50% tion can be a highly stressful topic, educational psychologists
Joyce Griffith and Sarah Brem have shown it is less stressful for
those teachers who are more confident and comfortable with the
37% material.33 So, taking evolution classes before beginning their
33%
teaching careers can directly increase teachers’ self-confidence,
which lowers their levels of stress heading into the course, and
makes them much more likely to teach in ways that live up to the
expectations of the National Research Council (and many other
scientific societies).
One teacher from Illinois summed up these findings well:
“After my undergraduate studies my perception of evolution was
inaccurate. It wasn’t til after I received a master of science that I
Completed Rated knowledge
felt like I had a good and accurate understanding of evolution and
a college-level above average
how natural selection happens.” A master’s degree in biology
course on evolution or exceptional
would probably be useful to biology teachers34—but such a goal
22 AMERicAN EdUcATOR | SUMMER 2012
cannot be accomplished right away. In the meantime, our More generally, the most effective long-term solution is for all
research suggests that future teachers would benefit from a more future high school biology teachers to be expected to have con-
rigorous pre-service education in biology and content-rich con- siderably more training in biological and all other science. Like-
tinuing education. wise, pre-service teachers intending to teach at the primary and
middle school levels would also benefit from additional oppor-
Preparing Teachers for the
tunities to expand their content expertise.
Coming Science wars
O
In the coming decade, the United States will have to make impor- ur hope is that educators will be supported by their
tant choices about energy policy (e.g., the safety of extracting oil administrators and community members so they can
and gas from shale deposits or of commissioning new nuclear teach evolution, climate change, the antiquity of the
reactors), the environment (e.g., the costs and benefits of policies universe, and any other socially controversial subject
to reduce carbon emissions), the wisdom of increasing our pro- with the same commitment to scientific accuracy as when they
duction of genetically modified foods, and much more. Because teach other topics in science. We would never ask students to
the disciplines of evolutionary biology, paleontology, climate debate or make up their own minds about whether the atmo-
science, and astrophysics each share similar methods with all sphere of Venus contains sulfuric acid, whether protons and
electrons have opposite charges, or which gene on chromo-
some 11 is linked to sickle cell disease. Rather, to the extent
possible at each grade level, we expect students to learn both
Teachers with creationist beliefs
scientific facts and what constitutes scientific evidence. As
their knowledge and sophistication increase, so too will their
completed fewer courses in biology,
understanding of the overwhelming evidence supporting
were less likely to major in a scientific evolution. Of course, teachers should emphasize that scien-
tific findings (and even scientific theories) are always subject
field, and were less likely to hold a
to revision, and are indeed sometimes revised—but not just
graduate degree in a scientific in the case of evolution! However, this openness should
never be a blank check that allows students to debate highly
discipline.
technical questions based on values and beliefs that come
from outside the science classroom. To the extent that stu-
dents are not convinced by the evidence before them, they
should simply be encouraged to explore the available evi-
sciences, any undermining of children’s trust in science—inten- dence further, in the reputable, peer-reviewed literature, and by
tional or not—will have important consequences. If students enrolling in higher-level courses. If students’ questions are met
come to think that science is simply a matter of one’s opinion, and with opportunities for further learning, the next generation not
that those opinions come from our values and faith, then it will only will have improved access to the STEM fields, but will become
be impossible for science to provide trusted, unbiased informa- curious, thoughtful, and engaged citizens. ☐
tion to citizens and policymakers.
What can be done to reverse this trend? In the case of evolu- Endnotes
tion, we concur with the National Center for Science Education 1. National Research Council, A Framework for K–12 Science Education: Practices, Crosscutting
Concepts, and Core Ideas (Washington, DC: National Academies Press, 2012), 1.
that “the most effective way for scientists to help to improve the
2. National Research Council, A Framework for K–12 Science Education, 162.
understanding of evolution” is at the pre-service level.35 Simply
3. National Academy of Sciences and Institute of Medicine, Science, Evolution, and
requiring a pre-service course in evolution is likely to provide Creationism (Washington, DC: National Academies Press, 2008), xiii.
cautious but well-intentioned teachers with the tools to address 4. F. James Rutherford and Andrew Ahlgren, Science for All Americans (New York: Oxford
University Press, 1991), 2.
and minimize pressure from their communities with a greater
5. Kenneth R. Miller, Finding Darwin’s God: A Scientist’s Search for Common Ground
degree of confidence. between God and Evolution (New York: Harper Perennial, 1999), 9.
Some have viewed our call for a required evolution course as 6. Neil Shubin, Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body
(New York: Random House, 2008).
nothing more than a call for indoctrination. But we believe the
7. For more on how scientific knowledge grows, see Susan Haack, Evidence and Inquiry:
charge is misplaced. Indoctrination is requiring students to accept Towards Reconstruction in Epistemology (Oxford: Wiley-Blackwell, 1995).
what they are taught whether or not there is evidence for it. But 8. Gallup, “Evolution, Creationism, Intelligent Design,” December 10–12, 2010, www.gallup.
com/poll/21814/evolution-creationism-intelligent-design.aspx.
we are calling for pre-service teachers to learn what the evidence
9. National Opinion Research Center, “General Social Survey 2010” (University of Chicago,
for evolution really is. This is the only way they can be expected March 15–August 12, 2010).
and empowered to teach their students about that evidence when 10. Pew Forum on Religion and Public Life, U.S. Religious Landscape Survey: Religious Beliefs
and Practices; Diverse and Politically Relevant (Washington, DC: Pew Research Center, June
they are in the classroom. This is not a panacea, of course; research 2008), 95.
shows that evolution education has little impact on conservative 11. See chapter 2 of Michael Berkman and Eric Plutzer, Evolution, Creationism, and the Battle
to Control America’s Classrooms (New York: Cambridge University Press, 2010).
Christians whose faith is a barrier to accepting evolution.36 But
12. Eric Plutzer and Michael Berkman, “The Polls—Trends: Evolution, Creationism, and the
our research suggests that completion of an evolution course can Teaching of Human Origins in Schools,” Public Opinion Quarterly 72, no. 3 (Fall 2008):
help teachers who already accept evolution do a better job of deal- 540–553.
13. See chapter 3 of Berkman and Plutzer, Evolution, Creationism, and the Battle.
ing with anti-science elements in their communities and of teach-
ing evolution with both integrity and confidence. (Continued on page 40)
AMERicAN EdUcATOR | SUMMER 2012 23